1. Field of the Invention
The present invention relates to data communication apparatus, system and method which are adopted in, e.g., a system to which plural electronic equipments are connected by a communication control bus capable of performing communication with mixture of control signals and data and in which data communication is performed among the plural equipments. Further, the present invention relates to a storage medium which computer-readably stores processing steps to perform the above method.
2. Related Background Art
In recent years, there has been adopted a home bus system which connects various electronic equipments (simply called as equipments or nodes hereinafter) together in a home. In the home bus system, e.g., audio/visual (AV) equipments such as a TV equipment, a stereo and the like, kitchen equipments such as a refrigerator, a microwave oven and the like, and home equipments such as a water bath, an interphone and the like are connected and associated to others, and each equipment in the home can be controlled by information communication among these equipments.
On the other hand, there has been popularized a data communication system using a public line outdoors. Especially, a user can perform the data communication at any place (not limited to home or office) by a PIAFS (PHS Internet Access Forum Standard) communication developed on a wired ISDN line or a wireless PHS.
Further, the PHS has an extension mode and a public mode. In the home, the user can perform the communication without charge (function as digital cordless slave) by using the extension mode. On the other hand, the user can directly perform the communication to the public line (function as simple digital portable telephone) outdoors by using the public mode.
However, in the conventional system such as the above home bus system, the data communication is performed based on a specific protocol. Further, in the conventional ISDN communication and PIAFS communication, the data communication is performed respectively based on specific protocols. For this reason, it is very difficult to perform the data communication between, e.g., the equipments in the home and the outside equipments (PHS and the like).
As above, according to conventional technique, the equipments in the home, the equipments in the office and the outdoor equipments respectively have different protocols for data communication, whereby it is impossible to freely perform the data communication among all of these equipments.